Base/Job: 3xThe difference between various monster's EXP rewards start to get out of hand the higher you go, so 3x is pretty ideal as to not cause some monsters to be vastly superior to others.

Drops: 10x for cards and equips, 1~3x for everything else. (Or just do Logarithmic like Playtester said)Like EXP rewards, monster drops get too imbalanced the higher up you go. Monsters that already had drops at 90% will cap out in value while other mobs that had 1% drops will suddenly become massively more valuable to hunt comparatively.